SETTING THE RECORD STRAIGHT (publ. 2/24/2014, page A4) In a story about how outdoor play improves intelligence, the digit span test was incorrectly reported as a measure of general intelligence. It was used as a specific stand-alone test to measure attention span in a larger study called “The Cognitive Benefits of Interacting with Nature.”

We know that outdoor play improves kids’ physical health. All that fresh air and exercise — what’s not to like? The truth is, there actually may be more to like. Outdoor play is increasingly linked scientifically to stronger mental muscle.

Parents have long thought of outdoor play as the icing on the cognitive cake: Finish your homework, attend to all of the after-school lessons and clubs intended to gain you admission to Stanford or Cal, and then, and only then, can you go out and play. A growing body of research, however, suggests that outdoor play offers such a positive bump in brain power, it should perhaps be a priority.

It’s not just a tug-of-war over time or the oft-blamed lure of technology. School recess and P.E. have been co-opted for more class time. At home, children are sidelined by everything from unsafe neighborhoods to homeowner association and city ordinances banning skateboards and basketball nets. It’s an uphill battle. However, experts say it’s one worth waging.

A 2012 study of 8,950 children, led by Pooja Tandon at the Seattle Children’s Research Institute, showed that nearly half of all preschoolers weren’t taken outside to play every day. This finding is particularly troubling to Tandon, acting assistant professor of pediatrics at the University of Washington, because, she points out, “outdoor play is beneficial for motor development, vision, cognition, vitamin D levels and mental health.”

That’s backed by results of a test called “digit span,” a standard measure of attention span, says Lara Honos-Webb, a Walnut Creek psychologist in private practice and the best-selling author of “The Gift of ADHD.”

“I read a series of numbers to you, and you repeat them back,” Honos-Webb says. “Studies using that test have shown that as little as a 20-minute walk in nature will boost your attention span.”

‘Nature as medicine’

Honos-Webb, who speaks widely on “nature as medicine,” marvels at the cognitive bang for your buck the outdoors provides.

“I love that it only requires such small doses — it’s so doable,” says the mother of two children, ages 9 and 10. Honos-Webb cites studies that show just having a room overlooking nature “can have an impact on impulse control and gratification delay.”

One school of thought about why nature has such an effect is the attention restoration theory: If you want to gain strength by lifting weights, you need to take a break between sessions for your muscles to recover; nature provides a similar break in attention for your brain.

The other theory, notes Honos-Webb, “is biophilia: This is what my brain was built for. Our brains evolved in nature. Now that we have light bulbs and iPads, nature has a calming effect. MRI tests confirm that nature produces chemical shifts in the brain.”

Amelia Rosenman experiences these shifts every week in her work as a naturalist, taking San Mateo County schoolchildren exploring at five-day outdoor research science camps in the Santa Cruz Mountains.

The kids enjoy a week of “detoxing” from videogames and other electronics, she explains. “They experience real life in real time. They open their eyes to the new world. And we see an incredible transformation in them from Monday to Friday.”

Self-directed play

Rosenman sees perhaps the “greatest transformation in children on the autism spectrum.” During an assembly for one group, she recalls a boy who couldn’t sit still, so Rosenman told him he could wander in a specified area. “And he found a rare, extremely well-camouflaged salamander, and he was the hero for the day.”

Indeed, self-direction may be key to the power of outdoor play for all children,﻿ says Joanne Finn, school psychologist for the Mt. Diablo Unified School District in Contra Costa County. “Outdoor spaces give kids more choices for creative play. Indoors, there are only a finite number of things a kid can do,” says Finn, who has a daughter, 12. But outdoors, she says, when kids are self-directed “they’re not going to do something rote — they’re going to want to problem-solve: gather materials for a fort, play hide-and-seek, explore new spaces. There’s an enthusiasm there. And when they’re excited, learning is heightened.”

Kids can get bored outdoors without the “instant gratification of the screen, particularly in circumstances they haven’t yet explored,” Finn says. Parents can give them ideas, but boredom allows the child “time to organize themselves and figure out what interests them,” Finn says. This kind of problem-solving hones executive thinking, she adds. “If a parent circumvents that process, they’ll never figure that out.”

Losing recess

Finland’s now-legendary rankings in the Program for International Student Assessment survey of reading, math and science scores started the global buzz linking outdoor play to cognitive improvement. The tiny Nordic nation’s superior rankings in 2008 were credited to its schools’ leisurely recesses — 15 minutes of outdoor play for every 45 minutes of instruction.

The newest PISA survey, released in December, shows America’s schools have fallen even further behind at a time when they have also continued to reduce recess time in favor of more class time, in addition to other factors. U.S. students now rank 26th out of 34 countries in math, 21st in science and 17th in reading. Finland, which minimizes homework and continues to strengthen its outdoor-play policies, with every schoolchild now getting at least 75 minutes per school day, is now ranked No. 1 in the world in science and No. 2 in math and reading.

“Americans think that we’d be damaging students by taking away all that classroom instruction,” Honos-Webb says. “But even when you compare (U.S.) middle schools within the same district, you see 95 percent of students excelling at math and science at schools where students go outside compared to 65 percent at schools where students stay inside.”

She notes that one district in Minnesota even showed a 54 percent reduction in suspensions in schools with outdoor environmental education programs.

As a result of such compelling science, Honos-Webb’s mantra to family clients has become “time in nature before homework. It’s the simplest intervention I do.” She has found that when parents take their kids to the park to do homework, the kids spend more time doing it. “It also reduces conflict between mother and child,” she adds.

‘Kids perform better’

Barry Savin, a teacher with Ruby Bridge Elementary School in Alameda, where most of the students qualify for free or reduced-price lunches, is also a crusader for outdoor play after 20 years working in special education.

“We know kids behave and perform better after exercise,” says Savin.

After outdoor play, Savin also notices a boost in self-confidence among his students, 25 to 40 percent of whom have hyperactivity issues. When kids with ADHD have trouble paying attention, Savin sends them outdoors for a run around the play structure. “It’s not always instant, but afterward they’re usually more focused,” she says.

“Kids today don’t have the balance,” Savin says. “They’re being rushed, so they’re anxious. And how do you relieve anxiety? Let them have fun and play.”

Rosenman also works with low-income children. “We have kids regularly who are seeing the stars for the first time … kids who live 45 minutes from the ocean and have never seen it. We hope we are planting the seed for the future.”

Most hopeful are signs of kids taking the reins of their own outdoor play.

“I always say to them on Friday, ‘You have the choice to take something from here and bring it into your life at home. What will it be?’ ” says Rosenman. “And sometimes, not always, but sometimes they say ‘playing outside!’ “

My niece works several jobs and is saving money for college application fees and expenses, but my brother and sister-in-law — who have notoriously poor money-management skills and compulsive spending habits — pressure her to lend them money, which they are slow to pay back, if at all.